Nearly 90 Chinese navy, coastguard ships reported near Taiwan, southern Japanese islands, East and South China Seas.

Taiwan’s military has raised the alert level to “high”, saying China restricted its airspace and deployed dozens of warships and coastguard vessels in waters around the island amid reports of a possible Chinese military drill.

In a statement on Monday, Taiwan’s Ministry of National Defense (MND) said it launched combat readiness drills and set up an emergency centre “factoring in enemy threats” in response to Beijing’s latest moves.

A Taipei security source told the Reuters news agency that China currently has nearly 90 navy and coastguard ships in waters near Taiwan, the southern Japanese islands and the East and South China Seas, of which about two-thirds are navy vessels.

In a statement, the Chinese Foreign Ministry spokeswoman Mao Ning pledged that China will “firmly defend” its sovereignty and “territorial integrity”, adding that Taiwan was an “inalienable” part of China.

Since the weekend, Taipei has been flagging the presence of 14 Chinese warships, seven military aircraft and at least four balloons, amid speculations of a possible military drill by Beijing.

Taiwan’s Defense Ministry said six of the aircraft crossed the median line of the Taiwan Strait, an unofficial demarcation zone between Taiwan and China. One of the balloons also brushed over the island’s northern tip, it added.

On Monday, Taiwan said China had set up seven zones of reserved airspace to the east of its eastern Fujian and Zhejiang provinces.

Such zones are temporarily reserved and allocated for a particular user during a set period, though other flights can pass through with permission from controllers, according to international rules.

“Any unilateral and irrational, provocative actions could seriously damage peace and stability in the Indo-Pacific and that will not be welcomed by the international community,” Taiwan’s Defense Ministry said.

Tensions have escalated in recent days following Taiwanese President William Lai Ching-te’s recent visit to Pacific allies, which included stops in the United States state of Hawaii and its territory of Guam.

China claims Taiwan, a self-ruled democracy of 23 million people, as its own territory, and bristles at other countries’ formal exchanges with Taiwan.

It has also pledged to annex Taiwan, through military force if necessary, sending ships and military planes near the island almost on a daily basis.

The US, like most countries, does not recognise Taiwan as a country but is its main unofficial backer and sells it arms.

On Friday, Taiwan’s Lai urged China to refrain from making threats.

“Raising your fists is not as good as opening your hands,” Lai added.

“No matter how many military exercises, warships and aircraft China sends to coerce neighbouring countries, it cannot win the respect of any country.”

Taiwan faces the constant threat of a military attack by China and relies heavily on US arms sales to boost its defences.